On Oct. 5, 2011, Jobs, the mastermind behind Apple's iPhone, iPad, iPod and Macs, died at the age of 56, surrounded by family members, after battling a form of pancreatic cancer and having a liver transplant.

"Steve was an amazing human being and left the world a better place. I think of him often and find enormous strength in memories of his friendship, vision and leadership," Apple CEO Tim Cook said in a letter to all Apple employees on Friday.

"He left behind a company that only he could have built and his spirit will forever be the foundation of Apple. We will continue to honor his memory by dedicating ourselves to the work he loved so much," Cook wrote.

In 2004, Jobs beat an unusual form of pancreatic cancer and in 2009 he was forced to get a liver transplant. Still, it was during those years that Jobs introduced some of the company's most iconic products, including the iPhone and the iPad. However, he became sick again and he finally announced on Aug. 24, 2011, that he was stepping down as CEO and handing over the reins to Cook.

Apple still thrives on the products Jobs created, but since his death industry experts have wondered whether Apple would be able to maintain its lead without his foresight and innovation. However, analysts point to Apple's recent successful iPhone launch, in which it sold 9 million phones in the first weekend, as further proof of the company's lead in the industry.

"Since the passing of Steve Jobs, Apple has continued to execute well from a product and business perspective," Ross Rubin, principal analyst at Rectile Research and a long time Apple watcher, told ABC News. "However, there continues to be a cloud of skepticism, primarily from stock watchers, about whether Apple can continue the streak it's been on with the iPod, iPhone and iPad in terms of inventing or re-inventing a category."

Those next categories, however, might also be influenced by Job's forethought and plans. In Walter Issacson's Steve Jobs biography, Jobs is quoted as saying he had figured out the solution to some of the major issues plaguing the television.

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Apple CEO Steve Jobs

"It will have the simplest user interface you could imagine. I finally cracked it,'" Jobs told Issacson. Apple has been rumored to be working on a television set of its own and Tim Cook has recently said that the area was of "intense interest" to the company.

"Steve Jobs was the master at 'just one more thing,'" Gene Munster, an analyst at Piper Jaffray & Co., told ABC News in 2011. "And this was his last one thing."

Cook has also said that wearable computing is interesting. Apple has been said to be working on a smartwatch or its iWatch, which would work with the iPhone to put some more functionality on your body.

"If Apple can launch into a new category in 2014, as many expect it will, this may finally silence the critics," Rubin said of those who have said Apple would suffer without Jobs at the helm. "However, there are other revenue opportunities for Apple, and it does not need to pin growth on any one new device."

Whether or not those products are introduced soon, it is clear that Jobs' legacy lives on at the company he built in his garage in 1976.

"There is no higher tribute to his memory," Cook said in the letter. "I know that he would be proud of all of you."